Expandable gastroretentive systems and dosage forms are generally prepared in a configuration suitable for ingestion (e.g. folded and fitted into an erodible confining element such as a capsule). After ingestion and erosion of the confining element, the gastroretentive dosage form expands in the stomach into an effective acting shape suitable for stomach retention (e.g. out of the capsule and unfolded) and eventually reduces size to pass through the pylorus or disintegrate.
There are many challenges in designing expandable gastroretentive dosage forms. One example is shelf life and storage limitation. Indeed, expandable gastroretentive dosage forms generally use elastic or semi-elastic materials to enable the shape changing from the effective swallowing configuration to the effective acting shape. However, maintaining stable physical properties of the elastic or semi-elastic materials during product shelf life is a major challenge because deterioration of the elastic capabilities directly impacts the ability to expand into the effective acting shape.